Product packaging

ABSTRACT

A method of fabricating packaging for a product comprises forming a plurality of conductive tracks on a sheet of material and forming a physical barrier, such as a hole, for impeding fluid flow between adjacent conductive tracks. The method may further comprise depositing first and second regions conductive fluid onto adjacent first and second conductive tracks either side of the physical barrier and mounting an electronic device having first and second terminals such that the electronic device forms a bridge over the physical barrier and the first ands second terminals contact the first and second conductive adjacent tracks.

FIELD OF THE INVENTION

The present invention relates to product packaging and/or printedmatter.

SUMMARY

According to the present invention there is provided a method offabricating packaging for a product and/or printed mater, the methodcomprising forming a plurality of conductive tracks on a sheet ofmaterial and forming a physical barrier for impeding fluid flow betweenadjacent conductive tracks.

Thus, the physical barrier can help to prevent, during a subsequentstep, conductive fluid from forming a short between the conductivetracks for example by preventing the two regions from being smudged intoeach other or being drawn together by capillary action.

Forming the physical barrier may comprise removing a portion of thesubstrate.

Removing the portion of the substrate may comprise forming a holethrough the sheet, for example punching the hole. Forming the physicalbarrier may comprise forming a trench in the sheet, for instance byimpressing a stamp into a surface of the sheet supporting the conductingtracks. Forming the physical barrier may comprise forming a wallupstanding from the sheet, for example by impressing a stamp into asurface which is reverse to a surface supporting the conducting tracks.

The barrier may be elongate having a longitudinal axis which istransverse to a shortest line between adjacent tracks.

Forming the plurality of conductive tracks on a sheet of material mayinclude forming at least one conductive track and breaking at least oneconductive track into more conductive tracks. Forming the physicalbarrier may break the at least one conductive track into the moreconductive tracks.

The method may comprise printing ink onto the sheet of material to formtext and/or image(s) and may comprise printing multiple inks to formcolour text and/or image(s).

The method may comprise cutting the sheet into smaller sections and maycomprise folding the sheet or a section of the sheet to form anenclosure.

The method may comprise depositing first and second regions conductivefluid onto first and second conductive adjacent tracks either side ofthe physical barrier; and mounting an electronic device having first andsecond terminals such that the electronic device forms a bridge over thephysical barrier and the first and second terminals contact the firstand second conductive adjacent tracks.

According to a second aspect of the present invention there is provideda method of fabricating packaging for a product and/or printed mater,the method comprising providing a printed sheet comprising a pluralityof conductive tracks disposed on a sheet of material and having aphysical barrier for impeding fluid flow between adjacent conductivetracks, depositing first and second regions conductive fluid onto firstand second conductive adjacent tracks either side of the physicalbarrier; and mounting an electronic device having first and secondterminals such that the electronic device forms a bridge over thephysical barrier and the first and second terminals contact the firstand second conductive adjacent tracks.

According to a third aspect of the present invention there is provided aprinted sheet for packaging a product and/or for use as printed matercomprising a sheet of material, a plurality of conductive trackssupported on sheet of material and a physical barrier for impeding fluidflow arranged between adjacent conductive tracks.

The barrier may comprise a trench in the sheet, a hole through the sheetand/or a wall upstanding from the sheet. The barrier may be elongate andhas longitudinal axis which is transverse to a shortest line betweenadjacent tracks.

The sheet material may comprise a packaging material or print medium andmay comprise cardboard or a plastic.

According to a fourth aspect of the present invention there is providedan assembly comprising a printed sheet, first and second regions ofconductive glue arranged on first and second conductive adjacent trackseither side of the physical barrier and an electronic device havingfirst and second terminals such that the electronic device forms abridge over the physical barrier and the first ands second terminalscontact the first and second conductive adjacent tracks.

The conductive glue may be fluid. The electronic device may be a lightemitting diode or a circuit board assembly.

The assembly may be configured as packaging for a product and/or asprinted matter.

According to a fifth aspect of the present invention there is providedapparatus for fabricating packaging for a product and/or printed matercomprising means for forming a plurality of conductive tracks on a sheetof material and means for forming a physical barrier for impeding fluidflow, said means configured to form said physical barrier betweenadjacent conductive tracks.

According to a sixth aspect of the present invention there is providedapparatus comprising a printer configured to form conductive tracks on asheet of material; and a press configured to form a physical barrier forimpeding fluid flow, said press configured to form said physical barrierbetween adjacent conductive tracks.

The press may be configured to punch a hole in the sheet to form thephysical barrier.

According to a seventh aspect of the present invention there is providedapparatus for fabricating packaging for a product and/or printed matercomprising means for providing a printed sheet comprising a plurality ofconductive tracks disposed on a sheet of material and having a physicalbarrier for impeding fluid flow between adjacent conductive tracks,means for depositing first and second regions conductive fluid ontofirst and second conductive adjacent tracks either side of the physicalbarrier and means for mounting an electronic device having first andsecond terminals such that the electronic device forms a bridge over thephysical barrier and the first ands second terminals contact the firstand second conductive adjacent tracks.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample, with reference to the accompanying drawings in which:

FIGS. 1 a-1 c illustrate how two regions of conductive glue can be drawntogether when mounting a device to a substrate;

FIGS. 2 a-2 c illustrate a side view, corresponding to FIGS. 1 a-1 c ofhow two regions of conductive glue can be drawn together when mounting adevice to a substrate;

FIG. 3 is a perspective view of packaging providing a printed circuitboard on which is mounted a device and which uses a slot in accordancewith the present invention;

FIG. 4 is a cross-sectional view through the printed circuit board andthe device taken along a line A-A′ in FIG. 3;

FIG. 5 is a cross-sectional view of packaging in which a trench is usedinstead of a slot;

FIG. 6 is a cross-sectional view of packaging in which a wall is usedinstead of a slot;

FIG. 7 is a schematic diagram of production line;

FIG. 7 a illustrates components of a gravure printing process;

FIGS. 8 a-8 e illustrate a method of fabricating packaging in accordancewith the present invention; and

FIG. 9 is a plan view of a different type of device.

DETAILED DESCRIPTION

A problem can arise when conductive glue, for example in the form ofmetallic particles suspended in a carrier, is used to attach electronicdevices, such as light emitting diodes, to conductive tracks.

Referring to FIGS. 1 a and 2 a, first and second separate regions 1 a, 1b of conductive glue are deposited on respective conductive tracks 2 a,2 b running on an upper surface 3 of a substrate 4. The conductive glueregions 1 a, 1 b are closely separated by a gap 5 (e.g. about 1 mm) andcontain, between them, sufficient excess glue for the glue to bridge thegap 5.

Referring to FIGS. 1 b and 2 b, an electronic device 6, such as a lightemitting diode, having at least first and second terminals 7 a, 7 b ispositioned over the conductive tracks 3 a, 3 b such that the deviceterminals 7 a, 7 b are aligned with the first and second regions 1 a, 1b respectively and is lowered onto the conductive tracks 3 a, 3 b.

As the device 6 is lowered, it touches the top (i.e. the meniscus) ofone or both of the conductive glue regions 1 a, 1 b. By capillaryaction, the regions 1 a, 1 b run together in a shallow space formedbetween the bottom of the device 6 and the top of the conductive tracks2 a, 2 b and substrate 4.

As shown in FIGS. 1 c and 2 c, a joined region 1 c is formed whichelectrically shorts the terminals 7 a, 7 b of the device 6.

It is noted that this problem does not tend affect conventional printedcircuit boards because solder tends to adhere to copper tracks and doesnot flow onto the substrate.

The problem may be addressed by increasing the size of the gap 5,minimising the amount of the glue and/or using glue which issufficiently viscous or reduces capillary action in some other way.

The present invention seeks to provide another solution this problem.

Referring to FIG. 3, packaging 9, in the form of a printed sheet ofcardboard folded into the shape of a box, provides a printed circuitboard 10 on which are mounted electrical devices 11 to provide circuitry12 which can be used for entertaining a user, for providing informationto the user or effecting some other user-directed function. For clarity,only part of the circuitry 12 is shown.

The packaging 9 may be a primary, secondary or tertiary form ofpackaging and may be used to package diverse forms of product such asfoods (e.g. a cereal box), medicines (e.g. a box containing a blisterpack of tablets or a tube of cream), household or office supplies, gamesand so on.

Electrical devices 11 may include discreet and integrated components andtypically include a battery or other power source, such as a solar cellor inductive loop, and one or more other devices such as light emittingdiodes, displays, speakers, buzzers, switches, sensors, transducers,integrated circuits and memory.

Referring also to FIG. 4, the packaging 9 includes a sheet of cardboard(herein also referred to as a “substrate”) supporting conductive tracks14 ₁, 14 ₂ (herein the tracks 14 ₁, 14 ₂ collectively are sometimesreferred to as the “circuit”), patterned layers of ink 15, 16, 17, 18(herein also referred to as a “text and images”) and, optionally, a toplayer of a clear varnish 19.

The conductive tracks 14 ₁, 14 ₂ comprise a conductive ink, for examplebased on graphite, and typically have a thickness of the order of 1, 10or 100 μm (usually dependent on the type of printing process used), awidth of the order of 100 μm or 1 mm and a length of the orders of 1 mmto 1 m. The conductive tracks 14 ₁, 14 ₂ typically have a line spacing(e.g. minimum spacing between two lines running parallel to one another)of the order of 10 μm, 100 μm or 1 mm. The layers of ink 15, 16, 17, 18comprise layers of cyan, yellow, magenta, black ink.

The printed circuit 14 ₁, 14 ₂ is formed under the text and images 15,16, 17, 18. However, the printed circuit 14 ₁, 14 ₂ can be locatedbetween and/or on top of the layers of ink 15, 16, 17, 18 and varnish19.

Packaging material other than cardboard may be used such card, aflexible plastic, such as polyethylene terephthalate (“PET”) andpolyimide, a flexible metallised plastic or a laminate of materials,e.g. card or paper between plastic.

As shown in FIG. 4, the printed circuit 14 ₁, 14 ₂ and the text andimages 15, 16, 17, 18 are formed on a first side 20 (herein alsoreferred to as a “face” or “surface”) of the substrate 13. However, bothsides of the substrate may be used.

An electronic device 11, in this example a light emitting diode, hasterminals 21 ₁, 21 ₂ connected to respective conductive tracks 14 ₁, 14₂ through windows (or “vias”) 22 ₁, 22 ₂ through the layers 15, 16, 17,18, 19. The terminals 21 ₁, 21 ₂ are connected to the tracks 14 ₁, 14 ₂using regions 23 ₁, 23 ₂ of conductive glue, for example comprisinggraphite or silver particles. The conductive glue 23 may also help tosecure the device 11. The glue regions 23 ₁, 23 ₂ may be referred to as“spots”, “blobs” or “patches”.

A rectangular hole or slot 24 is provided between sections 25 ₁, 25 ₂,(in this case the ends) of the conductive tracks 14 ₁, 14 ₂ to which theterminals 21 ₁, 21 ₂ are connected. The slot 24 need not be rectangular,but may be elliptical or irregularly shaped. Furthermore, the slot 24may trace a path, for example having one or more turns and which mayinclude straight or curved sections.

As will be explained in more detail later, the slot 24 is used toprovide a physical barrier to prevent the conductive glue 23, whenliquid or when more fluid, from spreading, particularly due to capillaryaction. In this and some other embodiments of the invention, the slot 24also serves to define one or more edges of the conductive tracks 14 ₁,14 ₂. Thus, a single line 14 (FIG. 8 a) can be printed or formed andbroken into two or more lines 14 ₁, 14 ₂ (FIG. 8 c) using one or moreslots 24.

Slots are positioned relative to the conductive tracks such that whenglue is placed on the tracks ready for a device to be connected, theglue is located to one side of a slot and the slot separates the gluefrom another part of the circuit where a short should be avoided. Gluemay be located immediately next to a slot or spaced some way away. Thus,the slots prevent glue from spreading over the surface of the substrateand/or over layers lying on the substrate 13 towards another trackand/or another spot of glue.

Other forms of physical barrier can be used.

Referring to FIGS. 5 and 6, the physical barrier may be a trench ortrough 25 or a wall 26 used to separate tracks 14 on a substrate 13. Thephysical barrier may comprise a combination of trench(es) and wall(s).The trench 25 or wall 26 can be formed by stamping or scoring. It willbe appreciated that a similar tool can be used for stamping and that thedifference between punching a hole and simply deforming the substratemay lie in the sharpness of the tool and/or the force or range ofmovement of the tool.

The profile (in cross section) of the trench 25 or wall 26 may bevertical and/or in some way discontinuous so as to inhibit the spread ofink or to break up a spreading film of ink.

Additionally or alternatively, the depth (d) of the trench 25 or height(h) of the wall 26 is chosen such there is sufficient clearance toinhibit capillary action and/or such that a typical volume of ink(typically of the order of picolitres) cannot bridge trench 25 or wall26. Values of depth and height can be found by routine experiment andtypically exceed 100 μm.

Typically the physical barrier need only have a width of order of 100μm, 1 mm or 10 mm, usually about 1 mm, and need only be effective whilethe glue is liquid or semi-liquid, typically for periods of the order of0.1, 1 or 10 seconds.

Referring to FIG. 7, apparatus 27 (or a “press”) for manufacturing thepackaging 9 (FIG. 3) generally comprises two parts 27 ₁, 27 ₂. A firstpart 27 ₁ is used to take a sheet 28 of material, such as cardboard, andproduce a printed sheet 29. A second part 27 ₂ takes the printed sheet29 and mounts devices 11 (FIG. 4) on the printed sheet 29 to form anassembled printed sheet 30.

The first and second parts 27 ₁, 27 ₂, may form parts of the sameproduction line. However, they may form different lines and be locatedat different sites or plants.

Referring also to FIG. 7 a, the apparatus is based on a gravure printingprocess having several stages, each having a gravure cylinder 31, adoctor blade 32 and ink reservoir 33 and an opposing impression cylinder34. However, other printing process can be used, such as offset,flexography, screen and inkjet printing processes and a mixture ofdifferent printing processes can be used in the same line.

In the first part 27 ₁ of the apparatus, the (unprinted) sheet 28 ofmaterial is paid out from a roller 35 and passes through a printingstage 36 used to print conductive tracks on the sheet 29, throughprinting stages 37, 38, 39, 40 used to print cyan, yellow, magenta,black graphic layers and, optionally, through a stage 41 for printing avarnish layer. Fewer graphic printing stages 37, 38, 39, 40 may be usedif, for example, a black-and-white or monochrome image is required.

A resulting sheet 29′ passes through a cutting and creasing stage 42used to crease the sheet 29′ for allowing the sheet to be easily foldedin the shape of a box and to cut the sheet 29′ to form a web or matrix,ready to be divided into smaller parts, if necessary to form windows.The cutting and creasing stage 42 also forms the physical barriers, forexample by stamping out holes in and/or between tracks, and/or byforming creases (troughs and/or wall) between tracks.

The printed sheet 29 is wound onto a take up roller 42 or fed directlyinto the second part 27 ₂ of the apparatus.

In the second part 27 ₂ of the apparatus, the printed sheet 29 passesthrough a gravure printing stage 44 used to print conductive glue on thesheet 29 and then passed through a device mounting stage 45 after whichthe assembled printed sheet 30 can be wound onto a take up roller 46.

The devices are provided on a web 47 and stamped out onto the sheet 29using a patterned cylinder 48 and an impression roller 49. However,other processes can be used such as “pick-and-place” robots.

The whole press 27 or the second part of the press 27 ₂ need not be aweb press, but can be a sheet-fed press. For example, rather than usingcylinders 48, 49 to cut and crease the sheet, boards can be usedinstead.

Referring to FIGS. 7 and 8, a method of fabricating the device will nowbe described.

Referring in particular to FIG. 8 a, a conductive track layer 14 and inklayers 15, 16, 17, 18 and varnish 19 are deposited on the sheet 13. Theink layers 15, 16, 17, 18 and/or varnish 19 may be printed with windows22 ₁, 22 ₂ onto the conductive track layer 14.

Referring in particular to FIG. 8 b, a stamping tool 50 stamps out aportion 51 of the sheet 13 and the overlying layers 14, 15, 16, 17, 18,19.

Referring in particular to FIG. 8 c, stamping leaves a hole 24 which, insome embodiments, serves in part, to define, first and second conductivetracks 14 ₁, 14 ₂. However, holes need not be used to break a conductivetrack.

Referring in particular to FIG. 8 d, spots of glue 23 ₁, 23 ₂ areapplied into the windows 22 ₁, 22 ₂, which open onto the tracks 14 ₁, 14₂.

Referring to FIG. 8 e, the device 11 is mounted during which theterminals 21 ₁, 21 ₂ are pressed into the windows 22 ₁, 22 ₂.

The slot 24 prevents a shallow channel 52 formed between an uppersurface 53 of the top-most layer 19 and an under surface 54 of thedevice 11 extending between the terminals 21 ₁, 21 ₂.

The use of physical barriers, particularly slots, can be used with morecomplex devices having more than two terminals.

Referring to FIG. 9, a printed circuit board assembly 55 having morethan two tracks 56 can be mounted onto corresponding tracks 57 of aprinted sheet 58 using conductive glue 59. The printed sheet 58 hasslots 60 punched out in regions between locations where glue is applied.

It will be appreciated that many modifications may be made to theembodiments hereinbefore described.

The use of physical barriers can be used printed sheets which are usedto provide printed mater which need not necessarily be used aspackaging. For example, the printed matter, for example in form ofplaying or trading card, can be used as a game or for information.

Instead of conductive ink, foil can be used to form the conductivetracks formed by (hot or cold) stamping or by masked etching of ametallised sheet.

A liquid, such as an ink, or semi-liquid, such as a paste may be usedinstead of glue.

The invention claimed is:
 1. A method of fabricating packaging for aproduct and/or printed matter, the method comprising: providing aprinted or metallized sheet comprising a flexible substrate supportingforming a plurality of conductive tracks on a face of the substrate;punching a hole through the sheet between adjacent conductive tracks toform a physical barrier for impeding fluid flow between the adjacentconductive tracks; printing ink onto the sheet of material to form textand/or image(s); depositing first and second regions of conductive fluidonto first and second conductive adjacent tracks either side of thehole; and mounting an electronic device having first and secondterminals such that the electronic device forms a bridge over the holeand the first and second terminals contact the first and secondconductive adjacent tracks.
 2. A method according to claim 1, whereinthe hole is elongate and has a longitudinal axis which is transverse toa shortest line between adjacent tracks.
 3. A method according to claim1, wherein forming the plurality of conductive tracks on the sheet ofmaterial includes forming at least one conductive track and breaking atleast one conductive track into more conductive tracks.
 4. A methodaccording to claim 3, wherein punching the hole breaks the at least oneconductive track into the more conductive tracks.
 5. A method accordingto claim 1, wherein printing the ink comprising: printing multiple inksto form colour text and/or image(s).
 6. A method according to claim 1,further comprising: cutting the sheet into smaller sections.
 7. A methodaccording to claim 1, further comprising: folding the sheet or a sectionof the sheet to form an enclosure.
 8. A method according to claim 1,wherein the steps are performed using a web-press.